1. Field
The present disclosure relates generally to interfacing between network components having different protocols and in particular to processing packets of data between devices connected to network data buses. Still, more particularly, the present disclosure relates a method and apparatus for monitoring a network data processing system and processing packets of data for errors and network configuration between components connected to data networks.
2. Background
Aeronautical Radio Inc. 664 (ARINC 664) is a standard for an avionics data network used in aircraft including commercial and transport aircraft. The ARINC 664 defines physical and electrical interfaces of a data network and data protocol for an aircraft's local area network. The ARINC 664 standard is based on the IEEE 802.3 standard and uses commercial off-the-shelf hardware. The Avionics Full Duplex Switched Ethernet (AFDX) network is built on the ARINC 664 standard. AFDX uses a switch tied to a number of end systems or line replaceable units. Each end system may be bridged using other switches on the network. AFDX also provides dual redundancy to increase availability on connectionless datagram communication. AFDX uses less wiring than previous networks. Since AFDX is full duplex, data can travel across a single wire in both directions, as opposed to the previous systems where two lines were used, one for each direction, in a simplex configuration.
AFDX uses a special protocol to provide deterministic timing and redundancy management. The deterministic timing allows for data to be transmitted between different systems within a specified time. To accomplish the timing, the amount of data per transmission is limited. AFDX comprises a data or logical link layer, network layer, transport layer, and application layer. AFDX also utilizes virtual links. Virtual links provide a unidirectional logic path from end system to end system instead of a normal Ethernet switch which routes packets of data based on machine access code address. AFDX routes packets of data using a virtual link identifier. A virtual link identifier is a 16-bit unsigned integer value that follows a constant 32-bit data field.
Virtual links are used by a network switch for three functions. Routing data packets, traffic policing, and size policing. Traffic policing may be, for example, monitoring network traffic in conformance with particular settings. For example, each virtual link has a “bandwidth allocation gap”. If a data packet with a particular virtual link is received in a period less than the specified bandwidth allocation gap, the switch does not forward the data packet to any configured port. Size policing may be, for example, measuring the minimum and maximum frame size of a particular data packet and only forwarding the packet if it is within the specified tolerance for a particular virtual link.
Currently, accessing and testing the AFDX network requires the use of proprietary hardware and software. The current software is used in combination with an application programming interface designed for the proprietary hardware and software. In addition to having to use the proprietary hardware and software, which are costly, these systems do not provide all desired capabilities. Since the systems are proprietary, it is difficult to alter them to provide additional capabilities.
Thus, it would be advantageous to have a method and apparatus that takes into account at least some of the issues discussed above, as well as possibly other issues.